1. Field of the Invention
This invention relates to dynamically optimized ballast, particularly to a ballast having a timer and a current-switching device to allow for multi-step output-levels, thereby eliminating the risk of systematic failures inherent with performing unregulated pulsing functions on HID (High Intensity Discharge) Systems.
2. Description of the Prior Art
At present, common HID lamps require use of ultra-high voltage to produce light from gas atoms excited by electric current. Typically, 12V or 24V DC (Direct Current) voltage is not enough to ignite the arc in the HID lamp, so a ballast is utilized between the HID lamp and Input Power to convert the DC voltage to AC (Alternating Current) voltage, and regulate the current supplied to the lamp throughout its operation.
However, it will generate a lot of problems when using the foregoing ballast with HID lamps of the vehicles or lighting appliances, as described below:
First, when the vehicles or lighting appliances are in use of HID lamps lighting, the foregoing ballast will provide the HID lamp a fixed maximum current resulting in the HID lamp achieving maximum brightness in an instant upon ignition. This standard way of igniting the arc in the HID lamp will result in a steady deterioration of HID lamp and reducing the service life of HID lamp. Moreover, unfortunately, an HID lamp is performing a flashing function common in aviation and automotive industries, the power source's repeated power-on and power-out (also known as “cold start”) will cause irreparable damage to the HID lamp and catastrophic failures. For example: during takeoff and landing, an aircraft commonly perform a pulsing action as a pre-caution to increase the visibility of the aircraft by other aircraft and land operations. This pulsing action on a foregoing HID System will have a high failure rate—for this reason, the foregoing ballast not only reduce the service efficiency of HID lamp, it will seriously affect the traffic safety.
Independently, the light production of an HID System commonly exceed the performance requirements that the system is being utilized for. For instance, when an aircraft is in a taxiing-state, the lighting requirement is only so that the environment is knowing of its existence; a sustained maximum brightness will only increase power consumption and deterioration of HID lamp.
For this reason(s), the inventor of this invention, having experience in designing and manufacturing lamps and its related products, understands and researched the problem of the foregoing ballast and hence devised this invention.